1. Field of the Invention
The present invention relates to a droplet ejection device that ejects a liquid.
2. Description of the Related Art
An inkjet recording device is known (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2008-513245) that includes a head provided with ejection apertures that eject a liquid for image recording (for example, ink), and records an image by ejecting droplets from the ejection apertures at a recording medium (for example, paper, a transparent substrate or the like).
This type of inkjet recording device, by supplying liquid stored in a storage tank to the head via supply piping with a supply pump and draining liquid in the head to the storage tank with a drainage pump, circulates the liquid between the storage tank, the supply piping, the head, and drainage piping. In this state, the liquid is ejected from the head so as to record an image represented by inputted image information on the recording medium. Pressures of the liquid inside each of the supply piping and the drainage piping are detected, and driving of each of the supply pump and the drainage pump is controlled such that pressure values of the liquid inside the supply piping and the drainage piping are at predetermined pressure values.
However, in the inkjet recording device described above, in response to a sudden pressure change of the liquid in the head when ejection of liquid by the head begins or when ejection ends or the like, undershooting or overshooting occurs before a pressure value of the liquid in the head converges to a predetermined pressure value. As a result, meniscuses at the ejection apertures are broken, and problems with ejection of the liquid may occur.